<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        #nav ul li{
            border: 2px solid #f60;
            padding: 10px 5px;
            margin: 20px 0;
        }
    </style>
</head>
<body>
    <div id="nav">
        <ul>
            <li>德玛西亚</li>
            <li>德玛西亚</li>
            <li>德玛西亚</li>
            <li>德玛西亚</li>
        </ul>
    </div>
    <ul>
        <li>德玛西亚</li>
        <li>德玛西亚</li>
        <li>德玛西亚</li>
        <li>德玛西亚</li>
    </ul>
</body>
</html>
<script src="js/jquery-1.10.1.js"></script>
<script>
    $(function () {
        $("#nav ul li").css("background","yellow");
    })
</script>